---
cve: "CVE-2026-64395"
severity: "HIGH"
cvss: 7.5
epss: "41%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-07-25 10:17:22"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-16T12:04:36+02:00"
---

# CVE-2026-64395

> 7.5 HIGH

## Beschreibung

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: require source read access for duplicate extents

FSCTL_DUPLICATE_EXTENTS_TO_FILE passes the source file directly to
vfs_clone_file_range() or vfs_copy_file_range() without checking the SMB
access mask granted to the source handle. A handle opened with attribute
access can consequently be used to copy file contents into an
attacker-readable destination.

Require FILE_READ_DATA on the source handle before either VFS operation,
matching other ksmbd data-copy paths.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Keine | good |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- Kernel ≥ 6.1.178
- Kernel ≥ 6.6.145
- Kernel ≥ 6.12.96
- Kernel ≥ 6.18.39
- Kernel ≥ 7.1.4

## Referenzen

- <https://git.kernel.org/stable/c/2d2ab6983620c2d60ce7db72133984ca3873b929>
- <https://git.kernel.org/stable/c/67bdad9cf01b25030e3bf00bbce6c309319d6663>
- <https://git.kernel.org/stable/c/b0d4d5cb846a1ddb7aaab9adfb5986e4540e6e5f>
- <https://git.kernel.org/stable/c/db231af842868268839f9f9619c68cb27830d8be>
- <https://git.kernel.org/stable/c/a10942af27832c2761d020863a46e79bebe0567d>
- <https://git.kernel.org/stable/c/cedff600f1642aa982178503552f0d007bc829c8>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-64395) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_